Reflects the known or estimated financial effect of the event, or transaction that occurred between the balance sheet date and the date the financial statements are issued or available to be issued.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Name Accounting Standards Codification
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 165
-Paragraph 13
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_SubsequentEventAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Subsequent Events (Details) (Public Service Company of New Mexico [Member], Electric Rate Case [Member], USD $) In Millions			6 Months Ended
	Aug. 08, 2011 Settlement of Regulatory Matter [Member]	Aug. 08, 2011 Capital Expenditures [Member] Rate Increase Due to Elimination of Rider [Member]	Jun. 30, 2011 Recorded Pre Tax Loss Not to be Recovered Through FPPAC [Member]	Jun. 30, 2011 Recorded Pre Tax Loss Not To Be Recovered Through Rates [Member]	Feb. 03, 2011 Capital Expenditures [Member]	Jun. 30, 2011	May 31, 2010
Subsequent Event [Line Items]
Amount of Regulatory Costs Not yet Approved					$ 20.0		$ 165.2
Public Utilities, Regulatory Costs Approved	72.10	20.00
Public Utilities, Collection of Regulatory Costs Forgoed of Under Collected Amount						10.0
Subsequent Event, Amount			$ 10.0	$ 7.5